MATH 1342 Name Elementary Statistical Methods Lab Ch.4 - Linear Regression Critical Thinking; Communication Skills; Empirical/Quantitative Skills 1. Researchers wondered whether the size of a person's brain was related to the individual's mental capacity. They selected a sample of right-handed introductory psychology students who had SAT scores higher than 1350. The subjects took the Wechsler Adult Intelligence Scale-Revised to obtain their IQ scores. MRI scans were performed at the same facility for the subjects. The scans consisted of 18 horizontal MR images. The computer counted all pixels with a nonzero gray scale in each of the 18 images, and the total count served as an index for brain size. IE a) On the axes above, draw a scatter diagram treating MRI count as the explanatory variable and IQ as the response variable. Label the graph! b) Test whether there is a linear relationship between MRI count and IQ.c) Predict the IQ score for a subject who has an MRI count of 850,000. 2. One of the biggest factors in determining the value of a home is the square footage. The following data represent the square footage and asking price (in thousands of dollars) for a random sample of homes for sale in Naples, Florida, in December 2010. Square 9 Footage Price ($) 154,000 59,900 69,000 69,900 70,000 79,900 80,000 89,000 89,900 -'La) On the axes above, draw a scatter diagram treating the square footage as the explanatory variable and asking price as the response variable. Label the graph! There is a linear relationship between the square footage and asking price. For each of the following, use the proper format for the monetary values. b) State the linear correlation coefficient c) Find the least-squares regression line. d) Predict the asking price if the square footage is 1500. e) Would a prediction for the asking price of a home that is 3350 square feet be reasonable? Why or Why not? Use a complete sentence and proper grammar. f) Interpret the slope. Use a complete sentence and proper grammar. 9) Is it reasonable to interpret the y-intercept? Why or why not